As a conventional steering lock device, one disclosed in a U.S. Pat. No. 7,121,126 is known. As shown in FIG. 10, the steering lock device 100 has a component housing chamber formed by a main frame 101 and a cover 102. In the component housing chamber, a lock member 103, a coil spring 104, a stopper 105, and a trigger 106 are provided. The lock member 103 shifts between its lock position for prohibiting rotation of a steering shaft (not shown) and its unlock position for allowing the rotation of the steering shaft. The coil spring 104 urges the lock member 103 toward a lock direction (downward in FIG. 10). The stopper 105 can hold the lock member at the lock position. The rod-shaped trigger 106 is formed integrally with the cover 102 and can hold the stopper 105 in its inoperable state.
In addition, the stopper 105 includes a stopper pin 107 and a stopper spring 108. The stopper pin 107 is held movably in a direction perpendicular to a moving direction of the lock member 103, and can be inserted into a recess 103a of the lock member 103. The stopper spring 108 is composed of a coil spring that urges the stopper pin 107 toward the lock member 103. Note that, although the stopper pin 107 is urged toward the lock member 103 (leftward in FIG. 10) by the stopper spring 108, it is normally held in a state where the stopper 105 is inoperable due to engagement between an end of the trigger 106 and the stopper pin 107.
By locking the steering shaft using the lock member 103, theft of a parked vehicle can be prevented. Even if the cover 102 is removed from the main frame 101 in order to directly operate the lock member 103 toward its unlock position, the trigger 106 is pulled out together with the cover, so that the stopper pin 107 is moved by the stopper spring 108 and thereby inserted into the recess 103a. As a result, since the lock member 103 is held at its lock position, an improper unlock of the lock member 103 can be restricted and thereby a forcible unlock of a lock state of the steering shaft can be prevented.